#include<iostream>
using namespace std;
#include<string>
void t1() {

	string s1;

	const char* str = "hello world";
	string s2(str);
	cout << s2 << endl;
	string s3(s2);
	cout << s3 << endl;

	string s4(10,'a');
	cout << s4 << endl;
}

int main() {

	t1();


	system("pause");
	return 0;
}